Update readme.md

Update README to indicate JDK 11 is required.

readme.md

@@ -35,7 +35,7 @@ Adds a Slack Alarm Notification type that handles alarm notifications through Sl
 Creates a Hello World component that can be dragged onto a window in the Designer.
 
 ## Requirements
-* The Java Development Kit (JDK) 1.8+ installed. You can download it on the [Java SDK Downloads](http://www.oracle.com/technetwork/java/javase/downloads/index-jsp-138363.html) page.
+* Java Development Kit (JDK) 11 installed. You can download it on the [Java SDK Downloads](http://www.oracle.com/technetwork/java/javase/downloads/index-jsp-138363.html) page.
 * Maven 3.+ installed. Linux users can use their package manager to install at the command line (ex: `sudo apt-get install maven`), and similarly OSX users using brew can `brew install maven`. Windows users can install via [Chocolatey](https://chocolatey.org/) (`choco install maven`) or by downloading the installer at the [Maven downloads](http://maven.apache.org/download.cgi_) page.
 * A running, 8.0+ version of Ignition to test your module in. If you don't already have Ignition installed head to the Inductive Automation [downloads](https://www.inductiveautomation.com/downloads/) page, download the correct package for your system and follow the installation instructions to get a gateway up and running.  
 * For development, you will want to allow unsigned modules. Open the `ignition.conf` file in the `data/` directory, then in the `wrapper.java.additional` section add a line like: `wrapper.java.additional.7=-Dignition.allowunsignedmodules=true` (the index does not matter).